Commit eec43a22 authored by Paul Burton's avatar Paul Burton Committed by Ralf Baechle
Browse files

MIPS: Save/restore MSA context around signals 



This patch extends sigcontext in order to hold the most significant 64
bits of each vector register in addition to the MSA control & status
register. The least significant 64 bits are already saved as the scalar
FP context. This makes things a little awkward since the least & most
significant 64 bits of each vector register are not contiguous in
memory. Thus the copy_u & insert instructions are used to transfer the
values of the most significant 64 bits via GP registers.

Signed-off-by: default avatarPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6533/


Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent a8ad1367

arch/mips/include/asm/sigcontext.h

+2 −0
Original line number Diff line number Diff line
@@ -32,6 +32,8 @@ struct sigcontext32 { 
	__u32		sc_lo2;

	__u32		sc_hi3;

	__u32		sc_lo3;

	__u64		sc_msaregs[32];	/* Most significant 64 bits */

	__u32		sc_msa_csr;

};

#endif /* _MIPS_SIM == _MIPS_SIM_ABI64 || _MIPS_SIM == _MIPS_SIM_NABI32 */

#endif /* _ASM_SIGCONTEXT_H */

arch/mips/include/uapi/asm/sigcontext.h

+8 −0
Original line number Diff line number Diff line
@@ -12,6 +12,10 @@ 
#include <linux/types.h>

#include <asm/sgidefs.h>



/* Bits which may be set in sc_used_math */

#define USEDMATH_FP	(1 << 0)

#define USEDMATH_MSA	(1 << 1)



#if _MIPS_SIM == _MIPS_SIM_ABI32



/*
@@ -37,6 +41,8 @@ struct sigcontext { 
	unsigned long		sc_lo2;

	unsigned long		sc_hi3;

	unsigned long		sc_lo3;

	unsigned long long	sc_msaregs[32];	/* Most significant 64 bits */

	unsigned long		sc_msa_csr;

};



#endif /* _MIPS_SIM == _MIPS_SIM_ABI32 */
@@ -70,6 +76,8 @@ struct sigcontext { 
	__u32	sc_used_math;

	__u32	sc_dsp;

	__u32	sc_reserved;

	__u64	sc_msaregs[32];

	__u32	sc_msa_csr;

};

arch/mips/kernel/asm-offsets.c

+3 −0
Original line number Diff line number Diff line
@@ -295,6 +295,7 @@ void output_sc_defines(void) 
	OFFSET(SC_LO2, sigcontext, sc_lo2);

	OFFSET(SC_HI3, sigcontext, sc_hi3);

	OFFSET(SC_LO3, sigcontext, sc_lo3);

	OFFSET(SC_MSAREGS, sigcontext, sc_msaregs);

	BLANK();

}

#endif
@@ -309,6 +310,7 @@ void output_sc_defines(void) 
	OFFSET(SC_MDLO, sigcontext, sc_mdlo);

	OFFSET(SC_PC, sigcontext, sc_pc);

	OFFSET(SC_FPC_CSR, sigcontext, sc_fpc_csr);

	OFFSET(SC_MSAREGS, sigcontext, sc_msaregs);

	BLANK();

}

#endif
@@ -320,6 +322,7 @@ void output_sc32_defines(void) 
	OFFSET(SC32_FPREGS, sigcontext32, sc_fpregs);

	OFFSET(SC32_FPC_CSR, sigcontext32, sc_fpc_csr);

	OFFSET(SC32_FPC_EIR, sigcontext32, sc_fpc_eir);

	OFFSET(SC32_MSAREGS, sigcontext32, sc_msaregs);

	BLANK();

}

#endif

arch/mips/kernel/r4k_fpu.S

+213 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
 * Copyright (C) 1999, 2001 Silicon Graphics, Inc.

 */

#include <asm/asm.h>

#include <asm/asmmacro.h>

#include <asm/errno.h>

#include <asm/fpregdef.h>

#include <asm/mipsregs.h>
@@ -245,6 +246,218 @@ LEAF(_restore_fp_context32) 
	END(_restore_fp_context32)

#endif



#ifdef CONFIG_CPU_HAS_MSA



	.macro	save_sc_msareg	wr, off, sc, tmp

#ifdef CONFIG_64BIT

	copy_u_d \tmp, \wr, 1

	EX sd	\tmp, (\off+(\wr*8))(\sc)

#elif defined(CONFIG_CPU_LITTLE_ENDIAN)

	copy_u_w \tmp, \wr, 2

	EX sw	\tmp, (\off+(\wr*8)+0)(\sc)

	copy_u_w \tmp, \wr, 3

	EX sw	\tmp, (\off+(\wr*8)+4)(\sc)

#else /* CONFIG_CPU_BIG_ENDIAN */

	copy_u_w \tmp, \wr, 2

	EX sw	\tmp, (\off+(\wr*8)+4)(\sc)

	copy_u_w \tmp, \wr, 3

	EX sw	\tmp, (\off+(\wr*8)+0)(\sc)

#endif

	.endm



/*

 * int _save_msa_context(struct sigcontext *sc)

 *

 * Save the upper 64 bits of each vector register along with the MSA_CSR

 * register into sc. Returns zero on success, else non-zero.

 */

LEAF(_save_msa_context)

	save_sc_msareg	0, SC_MSAREGS, a0, t0

	save_sc_msareg	1, SC_MSAREGS, a0, t0

	save_sc_msareg	2, SC_MSAREGS, a0, t0

	save_sc_msareg	3, SC_MSAREGS, a0, t0

	save_sc_msareg	4, SC_MSAREGS, a0, t0

	save_sc_msareg	5, SC_MSAREGS, a0, t0

	save_sc_msareg	6, SC_MSAREGS, a0, t0

	save_sc_msareg	7, SC_MSAREGS, a0, t0

	save_sc_msareg	8, SC_MSAREGS, a0, t0

	save_sc_msareg	9, SC_MSAREGS, a0, t0

	save_sc_msareg	10, SC_MSAREGS, a0, t0

	save_sc_msareg	11, SC_MSAREGS, a0, t0

	save_sc_msareg	12, SC_MSAREGS, a0, t0

	save_sc_msareg	13, SC_MSAREGS, a0, t0

	save_sc_msareg	14, SC_MSAREGS, a0, t0

	save_sc_msareg	15, SC_MSAREGS, a0, t0

	save_sc_msareg	16, SC_MSAREGS, a0, t0

	save_sc_msareg	17, SC_MSAREGS, a0, t0

	save_sc_msareg	18, SC_MSAREGS, a0, t0

	save_sc_msareg	19, SC_MSAREGS, a0, t0

	save_sc_msareg	20, SC_MSAREGS, a0, t0

	save_sc_msareg	21, SC_MSAREGS, a0, t0

	save_sc_msareg	22, SC_MSAREGS, a0, t0

	save_sc_msareg	23, SC_MSAREGS, a0, t0

	save_sc_msareg	24, SC_MSAREGS, a0, t0

	save_sc_msareg	25, SC_MSAREGS, a0, t0

	save_sc_msareg	26, SC_MSAREGS, a0, t0

	save_sc_msareg	27, SC_MSAREGS, a0, t0

	save_sc_msareg	28, SC_MSAREGS, a0, t0

	save_sc_msareg	29, SC_MSAREGS, a0, t0

	save_sc_msareg	30, SC_MSAREGS, a0, t0

	save_sc_msareg	31, SC_MSAREGS, a0, t0

	jr	ra

	 li	v0, 0

	END(_save_msa_context)



#ifdef CONFIG_MIPS32_COMPAT



/*

 * int _save_msa_context32(struct sigcontext32 *sc)

 *

 * Save the upper 64 bits of each vector register along with the MSA_CSR

 * register into sc. Returns zero on success, else non-zero.

 */

LEAF(_save_msa_context32)

	save_sc_msareg	0, SC32_MSAREGS, a0, t0

	save_sc_msareg	1, SC32_MSAREGS, a0, t0

	save_sc_msareg	2, SC32_MSAREGS, a0, t0

	save_sc_msareg	3, SC32_MSAREGS, a0, t0

	save_sc_msareg	4, SC32_MSAREGS, a0, t0

	save_sc_msareg	5, SC32_MSAREGS, a0, t0

	save_sc_msareg	6, SC32_MSAREGS, a0, t0

	save_sc_msareg	7, SC32_MSAREGS, a0, t0

	save_sc_msareg	8, SC32_MSAREGS, a0, t0

	save_sc_msareg	9, SC32_MSAREGS, a0, t0

	save_sc_msareg	10, SC32_MSAREGS, a0, t0

	save_sc_msareg	11, SC32_MSAREGS, a0, t0

	save_sc_msareg	12, SC32_MSAREGS, a0, t0

	save_sc_msareg	13, SC32_MSAREGS, a0, t0

	save_sc_msareg	14, SC32_MSAREGS, a0, t0

	save_sc_msareg	15, SC32_MSAREGS, a0, t0

	save_sc_msareg	16, SC32_MSAREGS, a0, t0

	save_sc_msareg	17, SC32_MSAREGS, a0, t0

	save_sc_msareg	18, SC32_MSAREGS, a0, t0

	save_sc_msareg	19, SC32_MSAREGS, a0, t0

	save_sc_msareg	20, SC32_MSAREGS, a0, t0

	save_sc_msareg	21, SC32_MSAREGS, a0, t0

	save_sc_msareg	22, SC32_MSAREGS, a0, t0

	save_sc_msareg	23, SC32_MSAREGS, a0, t0

	save_sc_msareg	24, SC32_MSAREGS, a0, t0

	save_sc_msareg	25, SC32_MSAREGS, a0, t0

	save_sc_msareg	26, SC32_MSAREGS, a0, t0

	save_sc_msareg	27, SC32_MSAREGS, a0, t0

	save_sc_msareg	28, SC32_MSAREGS, a0, t0

	save_sc_msareg	29, SC32_MSAREGS, a0, t0

	save_sc_msareg	30, SC32_MSAREGS, a0, t0

	save_sc_msareg	31, SC32_MSAREGS, a0, t0

	jr	ra

	 li	v0, 0

	END(_save_msa_context32)



#endif /* CONFIG_MIPS32_COMPAT */



	.macro restore_sc_msareg	wr, off, sc, tmp

#ifdef CONFIG_64BIT

	EX ld	\tmp, (\off+(\wr*8))(\sc)

	insert_d \wr, 1, \tmp

#elif defined(CONFIG_CPU_LITTLE_ENDIAN)

	EX lw	\tmp, (\off+(\wr*8)+0)(\sc)

	insert_w \wr, 2, \tmp

	EX lw	\tmp, (\off+(\wr*8)+4)(\sc)

	insert_w \wr, 3, \tmp

#else /* CONFIG_CPU_BIG_ENDIAN */

	EX lw	\tmp, (\off+(\wr*8)+4)(\sc)

	insert_w \wr, 2, \tmp

	EX lw	\tmp, (\off+(\wr*8)+0)(\sc)

	insert_w \wr, 3, \tmp

#endif

	.endm



/*

 * int _restore_msa_context(struct sigcontext *sc)

 */

LEAF(_restore_msa_context)

	restore_sc_msareg	0, SC_MSAREGS, a0, t0

	restore_sc_msareg	1, SC_MSAREGS, a0, t0

	restore_sc_msareg	2, SC_MSAREGS, a0, t0

	restore_sc_msareg	3, SC_MSAREGS, a0, t0

	restore_sc_msareg	4, SC_MSAREGS, a0, t0

	restore_sc_msareg	5, SC_MSAREGS, a0, t0

	restore_sc_msareg	6, SC_MSAREGS, a0, t0

	restore_sc_msareg	7, SC_MSAREGS, a0, t0

	restore_sc_msareg	8, SC_MSAREGS, a0, t0

	restore_sc_msareg	9, SC_MSAREGS, a0, t0

	restore_sc_msareg	10, SC_MSAREGS, a0, t0

	restore_sc_msareg	11, SC_MSAREGS, a0, t0

	restore_sc_msareg	12, SC_MSAREGS, a0, t0

	restore_sc_msareg	13, SC_MSAREGS, a0, t0

	restore_sc_msareg	14, SC_MSAREGS, a0, t0

	restore_sc_msareg	15, SC_MSAREGS, a0, t0

	restore_sc_msareg	16, SC_MSAREGS, a0, t0

	restore_sc_msareg	17, SC_MSAREGS, a0, t0

	restore_sc_msareg	18, SC_MSAREGS, a0, t0

	restore_sc_msareg	19, SC_MSAREGS, a0, t0

	restore_sc_msareg	20, SC_MSAREGS, a0, t0

	restore_sc_msareg	21, SC_MSAREGS, a0, t0

	restore_sc_msareg	22, SC_MSAREGS, a0, t0

	restore_sc_msareg	23, SC_MSAREGS, a0, t0

	restore_sc_msareg	24, SC_MSAREGS, a0, t0

	restore_sc_msareg	25, SC_MSAREGS, a0, t0

	restore_sc_msareg	26, SC_MSAREGS, a0, t0

	restore_sc_msareg	27, SC_MSAREGS, a0, t0

	restore_sc_msareg	28, SC_MSAREGS, a0, t0

	restore_sc_msareg	29, SC_MSAREGS, a0, t0

	restore_sc_msareg	30, SC_MSAREGS, a0, t0

	restore_sc_msareg	31, SC_MSAREGS, a0, t0

	jr	ra

	 li	v0, 0

	END(_restore_msa_context)



#ifdef CONFIG_MIPS32_COMPAT



/*

 * int _restore_msa_context32(struct sigcontext32 *sc)

 */

LEAF(_restore_msa_context32)

	restore_sc_msareg	0, SC32_MSAREGS, a0, t0

	restore_sc_msareg	1, SC32_MSAREGS, a0, t0

	restore_sc_msareg	2, SC32_MSAREGS, a0, t0

	restore_sc_msareg	3, SC32_MSAREGS, a0, t0

	restore_sc_msareg	4, SC32_MSAREGS, a0, t0

	restore_sc_msareg	5, SC32_MSAREGS, a0, t0

	restore_sc_msareg	6, SC32_MSAREGS, a0, t0

	restore_sc_msareg	7, SC32_MSAREGS, a0, t0

	restore_sc_msareg	8, SC32_MSAREGS, a0, t0

	restore_sc_msareg	9, SC32_MSAREGS, a0, t0

	restore_sc_msareg	10, SC32_MSAREGS, a0, t0

	restore_sc_msareg	11, SC32_MSAREGS, a0, t0

	restore_sc_msareg	12, SC32_MSAREGS, a0, t0

	restore_sc_msareg	13, SC32_MSAREGS, a0, t0

	restore_sc_msareg	14, SC32_MSAREGS, a0, t0

	restore_sc_msareg	15, SC32_MSAREGS, a0, t0

	restore_sc_msareg	16, SC32_MSAREGS, a0, t0

	restore_sc_msareg	17, SC32_MSAREGS, a0, t0

	restore_sc_msareg	18, SC32_MSAREGS, a0, t0

	restore_sc_msareg	19, SC32_MSAREGS, a0, t0

	restore_sc_msareg	20, SC32_MSAREGS, a0, t0

	restore_sc_msareg	21, SC32_MSAREGS, a0, t0

	restore_sc_msareg	22, SC32_MSAREGS, a0, t0

	restore_sc_msareg	23, SC32_MSAREGS, a0, t0

	restore_sc_msareg	24, SC32_MSAREGS, a0, t0

	restore_sc_msareg	25, SC32_MSAREGS, a0, t0

	restore_sc_msareg	26, SC32_MSAREGS, a0, t0

	restore_sc_msareg	27, SC32_MSAREGS, a0, t0

	restore_sc_msareg	28, SC32_MSAREGS, a0, t0

	restore_sc_msareg	29, SC32_MSAREGS, a0, t0

	restore_sc_msareg	30, SC32_MSAREGS, a0, t0

	restore_sc_msareg	31, SC32_MSAREGS, a0, t0

	jr	ra

	 li	v0, 0

	END(_restore_msa_context32)



#endif /* CONFIG_MIPS32_COMPAT */



#endif /* CONFIG_CPU_HAS_MSA */



	.set	reorder



	.type	fault@function

arch/mips/kernel/signal.c

+65 −8
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ 
#include <linux/bitops.h>

#include <asm/cacheflush.h>

#include <asm/fpu.h>

#include <asm/msa.h>

#include <asm/sim.h>

#include <asm/ucontext.h>

#include <asm/cpu-features.h>
@@ -46,6 +47,9 @@ static int (*restore_fp_context)(struct sigcontext __user *sc); 
extern asmlinkage int _save_fp_context(struct sigcontext __user *sc);

extern asmlinkage int _restore_fp_context(struct sigcontext __user *sc);



extern asmlinkage int _save_msa_context(struct sigcontext __user *sc);

extern asmlinkage int _restore_msa_context(struct sigcontext __user *sc);



struct sigframe {

	u32 sf_ass[4];		/* argument save space for o32 */

	u32 sf_pad[2];		/* Was: signal trampoline */
@@ -94,20 +98,60 @@ static int copy_fp_from_sigcontext(struct sigcontext __user *sc) 
	return err;

}



/*

 * These functions will save only the upper 64 bits of the vector registers,

 * since the lower 64 bits have already been saved as the scalar FP context.

 */

static int copy_msa_to_sigcontext(struct sigcontext __user *sc)

{

	int i;

	int err = 0;



	for (i = 0; i < NUM_FPU_REGS; i++) {

		err |=

		    __put_user(get_fpr64(&current->thread.fpu.fpr[i], 1),

			       &sc->sc_msaregs[i]);

	}

	err |= __put_user(current->thread.fpu.msacsr, &sc->sc_msa_csr);



	return err;

}



static int copy_msa_from_sigcontext(struct sigcontext __user *sc)

{

	int i;

	int err = 0;

	u64 val;



	for (i = 0; i < NUM_FPU_REGS; i++) {

		err |= __get_user(val, &sc->sc_msaregs[i]);

		set_fpr64(&current->thread.fpu.fpr[i], 1, val);

	}

	err |= __get_user(current->thread.fpu.msacsr, &sc->sc_msa_csr);



	return err;

}



/*

 * Helper routines

 */

static int protected_save_fp_context(struct sigcontext __user *sc)

static int protected_save_fp_context(struct sigcontext __user *sc,

				     unsigned used_math)

{

	int err;

	bool save_msa = cpu_has_msa && (used_math & USEDMATH_MSA);

	while (1) {

		lock_fpu_owner();

		if (is_fpu_owner()) {

			err = save_fp_context(sc);

			if (save_msa && !err)

				err = _save_msa_context(sc);

			unlock_fpu_owner();

		} else {

			unlock_fpu_owner();

			err = copy_fp_to_sigcontext(sc);

			if (save_msa && !err)

				err = copy_msa_to_sigcontext(sc);

		}

		if (likely(!err))

			break;
@@ -121,17 +165,28 @@ static int protected_save_fp_context(struct sigcontext __user *sc) 
	return err;

}



static int protected_restore_fp_context(struct sigcontext __user *sc)

static int protected_restore_fp_context(struct sigcontext __user *sc,

					unsigned used_math)

{

	int err, tmp __maybe_unused;

	bool restore_msa = cpu_has_msa && (used_math & USEDMATH_MSA);

	while (1) {

		lock_fpu_owner();

		if (is_fpu_owner()) {

			err = restore_fp_context(sc);

			if (restore_msa && !err) {

				enable_msa();

				err = _restore_msa_context(sc);

			} else {

				/* signal handler may have used MSA */

				disable_msa();

			}

			unlock_fpu_owner();

		} else {

			unlock_fpu_owner();

			err = copy_fp_from_sigcontext(sc);

			if (!err && (used_math & USEDMATH_MSA))

				err = copy_msa_from_sigcontext(sc);

		}

		if (likely(!err))

			break;
@@ -172,7 +227,8 @@ int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) 
		err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);

	}



	used_math = !!used_math();

	used_math = used_math() ? USEDMATH_FP : 0;

	used_math |= thread_msa_context_live() ? USEDMATH_MSA : 0;

	err |= __put_user(used_math, &sc->sc_used_math);



	if (used_math) {
@@ -180,7 +236,7 @@ int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) 
		 * Save FPU state to signal context. Signal handler

		 * will "inherit" current FPU state.

		 */

		err |= protected_save_fp_context(sc);

		err |= protected_save_fp_context(sc, used_math);

	}

	return err;

}
@@ -205,14 +261,14 @@ int fpcsr_pending(unsigned int __user *fpcsr) 
}



static int

check_and_restore_fp_context(struct sigcontext __user *sc)

check_and_restore_fp_context(struct sigcontext __user *sc, unsigned used_math)

{

	int err, sig;



	err = sig = fpcsr_pending(&sc->sc_fpc_csr);

	if (err > 0)

		err = 0;

	err |= protected_restore_fp_context(sc);

	err |= protected_restore_fp_context(sc, used_math);

	return err ?: sig;

}
@@ -252,9 +308,10 @@ int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) 
	if (used_math) {

		/* restore fpu context if we have used it before */

		if (!err)

			err = check_and_restore_fp_context(sc);

			err = check_and_restore_fp_context(sc, used_math);

	} else {

		/* signal handler may have used FPU.  Give it up. */

		/* signal handler may have used FPU or MSA. Disable them. */

		disable_msa();

		lose_fpu(0);

	}

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